A new sensor orbiting the Earth aboard NASAs satellite is now
collecting the most detailed measurements ever made of the seas surface
temperature every day all over the globe. Like a sophisticated
thermometer in space, the Moderate-resolution Imaging Spectroradiometer
(MODIS) is helping Earth scientists advance studies of how our worlds
oceans and atmosphere interact in ways that drive weather patterns and,
over the long term, define our climate.

The image above shows cold water upwelling near the coast of Peru
(purple) and joining the South Equatorial Current, which flows westward
across the Pacific Ocean. This MODIS sea surface temperature image from January 18, 2001
shows the ocean in normal conditions, but during an El Niño the waters
off Peru are much warmer. Cold waters are black and dark green. Blue,
purple, red, yellow, and white represent progressively warmer water.